Did predatory lending cause the housing bubble?

Or, for that matter, did the Community Reinvestment Act? Paul Krugman compares housing prices to commercial real estate prices and draws a conclusion I agree with:

From my perspective, the CRE bubble is highly significant; it gives the lie both to those who blame Fannie/Freddie/Community Reinvestment for the housing bubble, and those who blame predatory lending. This was a broad-based bubble.

This doesn't mean that predatory lending didn't exist. It simply means that predatory lending was a result of the housing bubble, not a cause of it.